Original subtitles

In the last chapters we've been adding some fine textures at the brick level,

but we've yet to add some big variation to the wall as a whole.

So far the only global variation we have is the bricks having different colors.

But as we covered when we added that color variation, this effect would be caused by the

bricks having different colors to start with, by mixing bricks from different batches for example.

But this is an old wall, so a lot of environmental conditions would

also have an effect on the its appearance. Things like weather exposure, for instance,

which wouldn't affect bricks individually, but rather the wall as a whole. One key aspect of

rich and interesting looking textures is having these different types and scales of variation.

So let's add some really large scale texture. Firstly, we'll need a Noise. Then we'll also need

a Texture Coordinate, and this time, we don't care about the brick coordinates at all, so let's just

take the plain Object coordinates, so that our noise maps to the wall as a continuous surface.

Let's take a look at the texture. Since we want large scale variation here,

we clearly need to make the noise much bigger, so let's find a suitable value. .2 seems alright.

The let's snap the nodes neatly onto the grid, and make some space for the rest of our setup.

We'll definitely want to have this texture affect the brightness,

so let's add yet another multiply node here, and connect our texture.

If we take a look at the color, we see some variation, but not that much,

and it's darkening the texture significantly, because all the values are below one,

so multiplying this reduces the values everywhere.

To get the effect we want, let's use another Map Range.

Let's compress the input range, to emphasize the texture,

and then let's widen the output range, to extend significantly beyond one.

This definitely helps to add some interesting variation, but we can still push it further.

Looking at the shader output, this still feels a bit too even.

One thing that we still haven't randomized at all is the saturation.

So to emphasize the brightness differences, let's also map this to the saturation.

Let's duplicate the Map Range, leaving the inputs connected, by using Ctrl+Shift+D.

Then, plugging it into the saturation, it looks pretty terrible. Clearly,

that's way too much saturation, and also, since we want to emphasize the brightness differences,

it's probably better to have lighter parts less saturated than the dark parts.

Let's just set both outputs to one, so that we have a neutral starting point.

Then let's reduce the saturation in the higher values, and let's increase the saturation in

the low values a bit. This immediately brings out the contrast in the texture,

because reducing the saturation pushes the colors closer to white,

which really contributes to the perceived brightness differences.

To push the brightness contrast contrast even more,

we can set the value variation to Smooth Step.

Then let's snap the nodes into place, and route the connections neatly.

And let's not forget our color coding! This texture is definitely low frequency,

so let's assign the node color accordingly,

copying the red color from another node, with our custom Ctrl+Shift+C shortcut.

And of course, let's take a moment to admire our creation with all that

Cycles displacement and path tracing goodness.